1. Field of the Invention
The present invention relates to a slipper sock of the type which includes a stretchable upper portion, a stretchable foot portion, and a protective bottom sole, as well as to a method of fabricating such a slipper sock.
2. The Prior Art
Foot coverings which includes stretchable upper portions, stretchable foot portions, and protective bottom soles are of course well known and are, for example, shown in detail in U.S. Pat. Nos. 3,863,272, 3,063,074, 3,032,898, 2,659,911, and 2,538,673. However, none of the prior art foot coverings are as conformable to the foot of the wearer or as comfortable to wear as the slipper socks according to the present invention. A brief summary of the teachings in these patents, as well as their deficiencies, follows.
The slipper sock according to Guille, U.S. Pat. No. 3,863,272, comprises a conventional knitted sock which has attached to the bottom of its foot portion a sole that is composed of a flexible, soft and wear-resistant material such as velvet-pile fabric, felt or tagged carpeting. A layer of plastic material is located on the face of the fabric sole in contact with the bottom of the foot portion of the sock, this plastic layer having imbedded therein the fibers of the bottom of the foot portion of the sock. The fabric sole is attached to the sides of the foot portion by way of a molded side portion composed of a plastic material such as polyvinyl chloride. In fabricating the slipper sock, the foot portion of the sock is fitted over a rigid foot-shaped forming block, the sole is placed at the bottom of a suitably-shaped cavity of a mold, the foot-shaped forming block (with sock foot portion positioned thereover) is placed within the mold, such that the bottom of the foot portion of the sock is applied against the sole, and a hot, pasty plastic material is injected into the mold, such that after cooling the noted side portion and the noted plastic layer located between the sole and the foot portion of the sock will be formed. In the embodiment of slipper sock according to Guille shown in FIGS. 7 and 8, an intercalary sole can be utilized between the foot portion of the sock and the fabric sole.
However, the slipper sock of Guille is totally different in construction from the slipper sock of the present invention (the slipper sock of the present invention includes no plastic adhesion layer connecting the entirety of the sole with the bottom of the foot portion of the sock, which adhesion layer stiffens and makes less comfortable the bottom of the foot portion of the sock, and it includes no molded side portion connecting the sole to the foot portion of the sock, which molded side portion reduces the conformability of the sock to the foot of the wearer--and thus its comfortableness), and the slipper sock of Guille is fabricated by a much different and much more complicated method as compared to that of the present invention.
The foot covering according to Scholl, U.S. Pat. No. 3,063,074, comprises a fabric slipper having an elastic upper and a cushion sole adhered to the foot portion of the fabric slipper (functional as either an insole or outsole, depending on how the fabric slipper is folded with respect to the cushion sole). The cushion sole is attached to the foot portion of the fabric slipper via a thermoplastic layer that permeates the fabric material of the fabric slipper and on the opposite surface of the cushion sole is located another layer of thermoplastic material to which is adhered a relatively thick layer of cushioning material. In fabricating the foot covering, the cushion sole is placed within a suitably-shaped opening in a form (the cushion sole having had the noted cushioning material already applied to one surface thereof), such that the thermoplastic adhesive (applied to the opposite surface) is exposed, the fabric slipper is then engaged over a foot-shaped last, the form is then heated such that the thermoplastic adhesive on the cushion sole therein is made tacky, and the last with fabric slipper thereon is then placed in the mold opening and pressed firmly upon the exposed adhesive layer on the cushion sole. Upon cooling of all the parts, the fabricated foot covering is lifted out of the form, the cushion sole being firmly bonded to the sole portion of the slipper.
The slipper sock of the present invention is totally different in construction and in method of fabrication as compared to the sock product and method of construction in Scholl, and in fact the slipper sock of the present invention, likewise in comparison to the slipper sock of Guille, is distinctly improved over that in Scholl since the use of a continuous adhesion layer between the sole and the bottom of the foot portion of the sock is completely avoided.
U.S. Pat. No. 3,032,898 to Servin shows a stretch-type slipper comprising two stitched-together knitted fabric upper portions which are connected at their bottom portions by a peripheral line of overlock stitching to a laminated sole, which itself forms the bottom of the foot portion of the slipper. The laminated sole comprises a center foam material having on one surface a knitted fabric material and on its other surface an impervious, imperforate synthetic resin layer. The noted stitching is caused to extend through the materials making up the laminated sole, through a ply of the fabric upper portions (the lowermost edges of the upper portions being folded back to create two bottom plies between which is located an elastic tension tape), and around the elastic tension tape, and back through the peripheral edges of the materials making up the laminated sole. The elastic tension tape helps to provide additional strength in holding the fabric upper portions to the laminate sole.
Although the slipper of Servin is indeed a stretch-type foot covering, its construction is much different from that of the present invention (the described slipper is not really a slipper "sock" since there is no knitted fabric bottom which is integral with the upper portions nor in a stretched condition), and its method of manufacture, whatever it is, is obviously not at all similar to that of the present invention.
Spack, U.S. Pat. No. 2,659,911, discloses a slipper sock and method for its production which includes a sock, an outer sole (made of sponge or foam) attached to the bottom wall of the foot portion of the sock by a layer of adhesive, and a welt which is adhered to the sides and peripheral portion of the sock foot portion, i.e., between the peripheral portion of the bottom wall of the sock foot portion and the outer sole. In fabricating the slipper sock, the sock is stretched over a last, the welt (having adhesive thereon) is applied to the outer longitudinal wall of the foot portion of the sock and then, after suitable applications of adhesive to the appropriate elements and suitable bending of the welt to contact the bottom wall of the foot portion of the sock, a suitably shaped and treated outer sole is pressed against the bottom wall of the sock foot portion and the welt at the periphery thereof until all the elements are firmly adhered together.
The slipper sock of the present invention, for reasons, noted previously with respect to the other patents, is totally distinct in construction and method of fabrication from the slipper sock of Spack.
Finally, the footwear article of Donahue, U.S. Pat. No. 2,538,673, includes an ordinary knitted sock to which is adhered, on the bottom of its foot portion, and via a layer of cement, a sole member 14 composed, for example, of natural or synthetic sponge rubber. In forming the footwear article, a pattern is inserted into the knitted sock and the sole member, which has had one surface thereof coated with first a layer of solvent-type cement and then a coating of latex-type rubber cement, is pressed against the outside of the bottom of the foot portion of the sock (which is supported internally by the pattern) sufficiently that the cement permeates the fibers of the sock fabric. The cement is allowed to partially set, and then the sock and attached sole are subjected to a great pressure, which then causes the cement to spread substantially laterally through the fibers of the sock, such that once dried, the cement will firmly grip and hold the fibers of the outwardly extending loops of the sock fabric.
The slipper sock of the present invention, for reasons noted previously with respect to the other patents, is totally distinct in construction and method of fabrication from the slipper sock of Donahue.